Glass shell manufacturing in space

Highly-uniform, hollow glass spheres (shells), which are used for inertial confinement fusion targets, were formed from metal-organic gel powder feedstock in a vertical furnace. As a result of the rapid pyrolysis caused by the furnace, the gel is transformed to a shell in five distinct stages: (a) surface closure of the porous gel; (b) generation of a closed-cell foam structure in the gel; (c) spheridization of the gel and further expansion of the foam; (d) coalescence of the closed-cell foam to a single-void shell; and (e) fining of the glass shell. The heat transfer from the furnace to the falling gel particle was modeled to determine the effective heating rate of the gel. The model predicts the temperature history for a particle as a function of mass, dimensions, specific heat, and absorptance as well as furnace temperature profile and thermal conductivity of the furnace gas. A model was developed that predicts the gravity-induced degradation of shell concentricity in falling molten shells as a function of shell characteristics and time

Performance analysis and development of pull-type production control strategies for evolutionary optimisation of closed-loop supply chains

The objective of this thesis is to establish a Closed-Loop Supply Chain (CLSC) design that is analysed through a series of simulation models, aimed at defining the highest performing production control strategy, whilst considering multiple related variables on both the forward and reverse flow of materials in manufacturing environments. Due to its stochastic nature, the reverse logistics side of the CLSC represents an increased source of variance for the inventory management and control strategies as it implies the erratic supply of returned materials, in addition to the very random customer demand, hence with highly variable inputs on both sides of the productive system, intrinsically inherent to this line of research. To test the operational performance of several pull-type production control strategies, a simulation-based research method was designed. The strategies experimented were: Hybrid Extended Kanban CONWIP special case (HEKC-II), Hybrid Kanban CONWIP (HKC), Dynamic Allocation Hybrid Extended Kanban CONWIP special case (DNC HEKC-II) and Dynamic Allocation Hybrid Kanban CONWIP (DNC HKC). All were tested in scenarios with high and low processing time variability and with 90% returned products and 40% returns from an open market system, therefore totaling 16 simulation models. Multi-objective evolutionary algorithms were utilised to generate the Pareto-optimum performance frontier with the objective of simultaneously minimising both performance metrics: The overall average work in progress (WIP) and the average backlog queue length (BL) for the entire CLSC. Processes used in the recovery and recycling of end of life manufactured goods were examined. This research method structures leading factors towards improved economic viability and sustainability of technologies required for the effective implementation of inventory control strategies on highly complex closed-loop supply chains with the focus on the performance metrics and optimum utilisation of resources available for the industry. The dynamic allocation strategies proved significant performance improvement, shifting the entire Pareto frontier forward with major advances on both metrics. Furthermore, it happened on all scenarios tested. The modified HEKC-II, with an optimisable parameter that enables it to be overwritten in a way that it can match the well-established HKC, also performed as originally intended and had better results than HKC in some cases, especially with the higher variability level. It also provided grounds for the suggested improvements and flexibilisation of the HEKC strategy. A major contribution of this thesis was the successful implementation of another advanced control methodology, entitled here the Intelligent Self-Designing Production Control Strategy, which provided maximum control performance. It consisted essentially of DNC HEKC-II with the following modifications: I) Extensive increase of dynamically allocated authorisation cards; II) Further anticipation of the time to trigger the change in the number of cards according to the finished goods buffer level, plus an acceleration/deceleration factor of this change; III) The capability of downsizing itself to become similar to HKC in an optimisation process if diverse production system conditions and variability would require. It displayed a very significant shift of the performance frontier

Glass shell manufacturing in space

A heat transfer model was developed that mathematically describes the heating and calculates the thermal history of a gel particle in free-fall through the furnace. The model parameters that greatly affect the calculations were found to be gel particle mass, geometry, specific heat, and furnace gas. Empirical testing of the model has commenced. The code calculations and the initial empirical testing results both indicate that the gel-to-shell transformation occurs early and rapidly in the thermal history of the gel particle, and that for current work the heat transfer rate is not a limitation in shell production

The weight of advice in older age.

Seeking advice from others may improve decision-making, particularly in older adults when cognitive decline can impair decision-making. This study measured the extent to which older adults rated the value of advice and used that advice in their decisions. Young (aged 18–37 years; n = 57) and older (aged 62–84 years; n = 56) adults completed a judge-advisor task incorporating advice from an expert and a novice. To capture interindividual differences in ratings of advice value and advice use (i.e., weight of advice), desire for autonomy, working memory, and fluid intelligence were assessed. Relative to young adults, older adults rated novice advice as being more valuable and were more likely to adjust their estimates based on expert and especially novice advice. Among older adults, poorer working memory and reduced preference for autonomous decision-making were associated with greater ratings of the value of novice advice, while better fluid intelligence was associated with increased ratings of the value of expert advice. Overall, older adults give more weight to advice and cognitive decline appears to compromise discrimination of the quality of that advice. (PsycInfo Database Record (c) 2021 APA, all rights reserved

Animal or Plant: Which Is the Better Fog Water Collector?

Occasional fog is a critical water source utilised by plants and animals in the Namib Desert. Fog basking beetles (Onymacris unguicularis, Tenebrionidae) and Namib dune bushman grass (Stipagrostris sabulicola, Poaceae) collect water directly from the fog. While the beetles position themselves optimally for fog water collection on dune ridges, the grass occurs predominantly at the dune base where less fog water is available. Differences in the fog-water collecting abilities in animals and plants have never been addressed. Here we place beetles and grass side-by-side in a fog chamber and measure the amount of water they collect over time. Based on the accumulated amount of water over a two hour period, grass is the better fog collector. However, in contrast to the episodic cascading water run-off from the grass, the beetles obtain water in a steady flow from their elytra. This steady trickle from the beetles' elytra to their mouth could ensure that even short periods of fog basking – while exposed to predators – will yield water. Up to now there is no indication of specialised surface properties on the grass leafs, but the steady run-off from the beetles could point to specific property adaptations of their elytra surface

Some Secrets of Fluorescent Proteins: Distinct Bleaching in Various Mounting Fluids and Photoactivation of cyan fluorescent proteins at YFP-Excitation

Background
The use of spectrally distinct variants of green fluorescent protein (GFP) such as cyan or yellow mutants (CFP and YFP, respectively) is very common in all different fields of life sciences, e.g. for marking specific proteins or cells or to determine protein interactions. In the latter case, the quantum physical phenomenon of fluorescence resonance energy transfer (FRET) is exploited by specific microscopy techniques to visualize proximity of proteins.

Methodology/Principal Findings
When we applied a commonly used FRET microscopy technique - the increase in donor (CFP)-fluorescence after bleaching of acceptor fluorophores (YFP), we obtained good signals in live cells, but very weak signals for the same samples after fixation and mounting in commercial microscopy mounting fluids. This observation could be traced back to much faster bleaching of CFP in these mounting media. Strikingly, the opposite effect of the mounting fluid was observed for YFP and also for other proteins such as Cerulean, TFP or Venus. The changes in photostability of CFP and YFP were not caused by the fixation but directly dependent on the mounting fluid. Furthermore we made the interesting observation that the CFP-fluorescence intensity increases by about 10 - 15% after illumination at the YFP-excitation wavelength – a phenomenon, which was also observed for Cerulean. This photoactivation of cyan fluorescent proteins at the YFP-excitation can cause false-positive signals in the FRET-microscopy technique that is based on bleaching of a yellow FRET acceptor.

Conclusions/Significance
Our results show that photostability of fluorescent proteins differs significantly for various media and that CFP bleaches significantly faster in commercial mounting fluids, while the opposite is observed for YFP and some other proteins. Moreover, we show that the FRET microscopy technique that is based on bleaching of the YFP is prone to artifacts due to photoactivation of cyan fluorescent proteins under these conditions

Release of sICAM-1 in Oocytes and In Vitro Fertilized Human Embryos

Background: During the last years, several studies have reported the significant relationship between the production of soluble HLA-G molecules (sHLA-G) by 48–72 hours early embryos and an increased implantation rate in IVF protocols. As consequence, the detection of HLA-G modulation was suggested as a marker to identify the best embryos to be transferred. On the opposite, no suitable markers are available for the oocyte selection. Methodology/Principal Findings: The major finding of the present paper is that the release of ICAM-1 might be predictive of oocyte maturation. The results obtained are confirmed using three independent methodologies, such as ELISA, Bio-Plex assay and Western blotting. The sICAM-1 release is very high in immature oocytes, decrease in mature oocytes and become even lower in in vitro fertilized embryos. No significant differences were observed in the levels of sICAM-1 release between immature oocytes with different morphological characteristics. On the contrary, when the mature oocytes were subdivided accordingly to morphological criteria, the mean sICAM-I levels in grade 1 oocytes were significantly decreased when compared to grade 2 and 3 oocytes. Conclusions/Significance: The reduction of the number of fertilized oocytes and transferred embryos represents the main target of assisted reproductive medicine. We propose sICAM-1 as a biochemical marker for oocyte maturation and grading

Galaxy And Mass Assembly: automatic morphological classification of galaxies using statistical learning

© 2018 The Author(s). We apply four statistical learning methods to a sample of 7941 galaxies (z < 0.06) from the Galaxy And Mass Assembly survey to test the feasibility of using automated algorithms to classify galaxies. Using 10 features measured for each galaxy (sizes, colours, shape parameters, and stellar mass), we apply the techniques of Support Vector Machines, Classification Trees, Classification Trees with Random Forest (CTRF) and Neural Networks, and returning True Prediction Ratios (TPRs) of 75.8 per cent, 69.0 per cent, 76.2 per cent, and 76.0 per cent, respectively. Those occasions whereby all four algorithms agree with each other yet disagree with the visual classification ('unanimous disagreement') serves as a potential indicator of human error in classification, occurring in ~ 9 per cent of ellipticals, ~ 9 per cent of little blue spheroids, ~ 14 per cent of early-type spirals, ~ 21 per cent of intermediate-type spirals, and ~ 4 per cent of late-type spirals and irregulars. We observe that the choice of parameters rather than that of algorithms is more crucial in determining classification accuracy. Due to its simplicity in formulation and implementation, we recommend the CTRF algorithm for classifying future galaxy data sets. Adopting the CTRF algorithm, the TPRs of the five galaxy types are: E, 70.1 per cent; LBS, 75.6 per cent; S0-Sa, 63.6 per cent; Sab-Scd, 56.4 per cent, and Sd-Irr, 88.9 per cent. Further, we train a binary classifier using this CTRF algorithm that divides galaxies into spheroid-dominated (E, LBS, and S0-Sa) and disc-dominated (Sab-Scd and Sd-Irr), achieving an overall accuracy of 89.8 per cent. This translates into an accuracy of 84.9 per cent for spheroid-dominated systems and 92. 5 per cent for disc-dominated systems

The Good, the Bad, and the Rare: Memory for Partners in Social Interactions

For cooperation to evolve via direct reciprocity, individuals must track their partners' behavior to avoid exploitation. With increasing size of the interaction group, however, memory becomes error prone. To decrease memory effort, people could categorize partners into types, distinguishing cooperators and cheaters. We explored two ways in which people might preferentially track one partner type: remember cheaters or remember the rare type in the population. We assigned participants to one of three interaction groups which differed in the proportion of computer partners' types (defectors rare, equal proportion, or cooperators rare). We extended research on both hypotheses in two ways. First, participants experienced their partners repeatedly by interacting in Prisoner's Dilemma games. Second, we tested categorization of partners as cooperators or defectors in memory tests after a short and long retention interval (10 min and 1 week). Participants remembered rare partner types better than they remembered common ones at both retention intervals. We propose that the flexibility of responding to the environment suggests an ecologically rational memory strategy in social interactions